Abstract

Worldwide evidence indicates a reduction in the rate of yield growth for many key food crops, but reasons for this remain unclear. Here, we quantitatively demonstrate the role and significance of different drivers (climate change, fertilizer use, change in rice cultivation area, and changes in crop varieties and management) in explaining rice yield development in China, through the use of two temporally and regionally calibrated crop models -- EPIC and DSSAT. China's rice yield has increased from 4324 kg/ha in 1981 to 6553 kg/ha in 2010, with an evidently slowing growth rate over this time period. The observed flattening growth trend is well captured by both crop models. EPIC simulated a yield increase of 2024 kg/ha up to 2010, with agricultural intensification together with increased application of chemical fertilizer and improved crop varieties and management dominating the growth, contributing 64% and 37% respectively, while changes in climate (2%) and cultivation area (-3%) contributed only minimally. The recent slowing rate of rice yield growth is largely interpreted as a decreasing relative contribution of fertilizer, that is not being compensated by relative benefits from improved varieties and management. We also find that adaptation to climate change may have contributed to the observed increase of rice yield by facilitating the relocation of rice growing areas and the adoption of improved rice cultivars. Crop model simulations demonstrate that additional yield increases could be achieved through the introduction of rice cultivars and management optimized for climate, suggesting viable options for reversing the slowing of rice yield growth. Moving towards an agriculture that utilizes climate benefits more smartly is one of the solutions to enhance future food supply in China.